Problem: Simplify the expression. $(7y^{3}+3y)(6y^{4}-7y^{3})$
Answer: First use the distributive property. $ 7 y^3 (6 y^4) + 7 y^3 (-7 y^3) + 3 y (6 y^4) + 3 y (-7 y^3) $ Simplify. $42y^{7}-49y^{6}+18y^{5}-21y^{4}$